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Safety of Class 1C Antiarrhythmic Drugs in Patients With CAD
Quick Takes
- Among patients treated with antiarrhythmic drugs for atrial fibrillation, Class 1C agents were independently associated with better event-free survival than Class III agents (excluding amiodarone and dronedarone).
- While the degree of CAD based on clinical diagnosis was not an independent predictor of event-free survival, there was a significant interaction between 1C use and obstructive CAD, suggesting poorer survival among this group than those on Class III agents.
- Given multiple limitations of the current analysis, these data should be considered hypothesis generating and additional prospective studies are needed to validate current findings.
Study Questions:
What is the safety and feasibility of treatment with Class 1C agents in patients with varying degrees of coronary artery disease (CAD) in a large serial, real-world cohort?
Methods:
The investigators retrospectively identified all patients at their institution from January 2005 to February 2021 on a Class 1C agent (n = 3,445), and on sotalol or dofetilide (n = 2,216) as controls, excluding those with a prior history of ventricular tachycardia (VT), implantable cardioverter-defibrillator placement, or nonrevascularized myocardial infarction. Baseline clinical characteristics included degree of CAD (categorized as: none, nonobstructive, or obstructive), other comorbid illness, and medication use. Clinical outcomes, including survival, were ascertained. They performed Cox regression analysis to evaluate the effect of 1C use on event-free survival across varying degrees of CAD. Differences in survival between groups were evaluated with the log-rank test.
Results:
After adjusting for baseline characteristics, there was an independent association between 1C use and improved mortality. However, there was an interaction between 1C use and degree of CAD (compared to sotalol) demonstrating poorer event-free survival among those with obstructive coronary disease (hazard ratio, 3.80; 95% confidence interval, 1.67-8.67; p = 0.002).
Conclusions:
The authors report that among select patients with nonobstructive CAD and without a history of VT, 1C agents are not associated with increased mortality.
Perspective:
This real-world cohort study of patients treated with antiarrhythmic drugs for atrial fibrillation reports that Class 1C agents were independently associated with better event-free survival than Class III agents (excluding amiodarone and dronedarone). Furthermore, while the degree of CAD based on clinical diagnosis was not an independent predictor of event-free survival, there was a significant interaction between 1C use and obstructive CAD, suggesting poorer survival among this group than those on Class III agents. Overall, these data suggest that in appropriately selected patients with atrial arrhythmias and nonobstructive coronary disease, 1C agents may be safe. Given multiple limitations of the current analysis, these data should be considered hypothesis generating and additional prospective studies are needed to validate current findings and also evaluate the role of revascularization of obstructive CAD and safety of 1C agents for nonventricular arrhythmias.
Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Cardiovascular Care Team, Invasive Cardiovascular Angiography and Intervention, Prevention, Atherosclerotic Disease (CAD/PAD), Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Cardiac Surgery and Arrhythmias, Interventions and Coronary Artery Disease
Keywords: Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Atrial Fibrillation, Coronary Artery Disease, Coronary Disease, Myocardial Revascularization, Secondary Prevention, Survival, Tachycardia, Ventricular
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